Started work on area light, cleaned up ray.c and clamped colors

6 files changed, 144 insertions, 80 deletions

diff --git a/main.c b/main.c
index 56d565b..4bb068c 100644
--- a/main.c
+++ b/main.c
@@ -2,6 +2,7 @@
 #include <math.h>
 #include <stdlib.h>
 #include <pthread.h>
+#include <string.h>
 
 #include "vector.h"
 #include "ray.h"
@@ -26,7 +27,7 @@ typedef struct {
 unsigned percent = 0;
 pthread_mutex_t percentlock;
 
-#define OBJECTS 9
+#define OBJECTS 10
 #define MATERIALS 6
 #define LIGHTS 1
 
@@ -62,16 +63,13 @@ int main()
 	material_t *m = add_material(cont);
 	vector_set(&m->color, 0.4, 0.4, 1);
 	m->defuse = 1;
-	m->specular = 0.0;
+	m->specular = 0;
 	m->shine = 80;
 	m->reflective = 0.0;
 
-	material_t *m3 = add_material(cont);
-	vector_set(&m3->color, 1, 0.3, 0.1);
-	m3->defuse = 0.95;
-	m3->specular = 0.0;
-	m3->shine = 80;
-	m3->reflective = 0.05;
+	material_t *ml = add_material(cont);
+	vector_set(&ml->color, 1, 1, 1);
+	ml->emissive = 1;
 
 	material_t *m2 = add_material(cont);
 	vector_set(&m2->color, 1, 1, 1);
@@ -111,7 +109,7 @@ int main()
 	o->m = m;
 
 	o = add_object(cont, TYPE_SPHERE);
-	vector_set(&o->sph.center, 1, 1, 5);
+	vector_set(&o->sph.center, 1, 1, 1);
 	o->sph.radius = 1;
 	o->m = m;
 
@@ -144,11 +142,19 @@ int main()
 	vector_set(&o->pl.start, 5, 0, 0);
 	vector_set(&o->pl.norm, 1, 0, 0);
 	o->m = mplred;
+	
+	// Used for the light ball
+	/*
+	o = add_object(cont, TYPE_SPHERE);
+	vector_set(&o->sph.center, 2, -2, 8);
+	o->sph.radius = 1;
+	o->m = ml;
+	*/
 
-	light_t *l = add_light(cont);
-	vector_set(&l->pos, 3, 0, 1);
-	color_set(&l->defuse, 1, 1, 1);
-	color_set(&l->specular, 0.5, 0.5, 0.5);
+	light_t *l = add_light(cont, TYPE_L_POINT);
+	vector_set(&l->point.pos, 2, 0, 5);
+	color_set(&l->color, 1, 1, 1);
+	l->radiance = 10;
 
 	pgm_write_header(stdout, TESTW, TESTH);
 
@@ -210,6 +216,7 @@ void *worker_func(void *arg) {
 			//color_t c;
 			seed = x * y;
 			ray_trace(&cont->space, TESTW - x, TESTH - y, 2, c, &seed);
+			color_clamp(c);
 		}
 
 		if (y % PERCENTSTEP == 0) {
diff --git a/pgm.c b/pgm.c
index eb0c101..4280486 100644
--- a/pgm.c
+++ b/pgm.c
@@ -10,6 +10,33 @@ int pgm_write_header(FILE *fp, unsigned int w, unsigned int h)
 	return fprintf(fp, "P3\n%d %d\n%d\n", w, h, COLOR_MAX);
 }
 
+/*
+ * Diden't really look that nice. 
+void color_clamp(color_t *c)
+{
+	// Fint the max of the 3 values
+	COORD_T max = c->r > c->g ? c->r : c->g;
+	max = max > c->b ? max : c->b;
+
+	if (max <= 1.0) {
+		return;
+	}
+
+	// Scale everything by this
+	color_scale(c, c, (COORD_T) 1 / max);
+}
+*/
+
+#define MAXOUT(v) ( if (v > 1) { v = 1; } )
+
+void color_clamp(color_t *c)
+{
+	// Just max them out
+	if (c->r > 1) { c->r = 1; }
+	if (c->g > 1) { c->g = 1; }
+	if (c->b > 1) { c->b = 1; }
+}
+
 int pgm_write_pixel(FILE *fp, color_t *c)
 {
 	return fprintf(fp, "%.0lf %.0lf %.0lf\n", c->r * COLOR_MAX, c->g * COLOR_MAX, c->b * COLOR_MAX);
@@ -26,28 +53,18 @@ color_t *color_set(color_t *c, COORD_T r, COORD_T g, COORD_T b)
 
 color_t *color_add(color_t *dest, color_t *a, color_t *b)
 {
-	COORD_T tmp = a->r + b->r;
-	dest->r = tmp > 1 ? 1 : tmp;
-
-	tmp = a->g + b->g;
-	dest->g = tmp > 1 ? 1 : tmp;
-
-	tmp = a->b + b->b;
-	dest->b = tmp > 1 ? 1 : tmp;
+	dest->r = a->r + b->r;
+	dest->g = a->g + b->g;
+	dest->b = a->b + b->b;
 
 	return dest;
 }
 
 color_t *color_scale(color_t *dest, color_t *a, COORD_T b)
 {
-	COORD_T tmp = a->r * b;
-	dest->r = tmp > 1 ? 1 : tmp;
-
-	tmp = a->g * b;
-	dest->g = tmp > 1 ? 1 : tmp;
-
-	tmp = a->b * b;
-	dest->b = tmp > 1 ? 1 : tmp;
+	dest->r = a->r * b;
+	dest->g = a->g * b;
+	dest->b = a->b * b;
 
 	return dest;
 }
diff --git a/pgm.h b/pgm.h
index 5a6621d..91c756b 100644
--- a/pgm.h
+++ b/pgm.h
@@ -9,6 +9,8 @@ typedef struct {
 	COORD_T r, g, b;
 } color_t;
 
+void color_clamp(color_t *c);
+
 color_t *color_set(color_t *c, COORD_T r, COORD_T g, COORD_T b);
 color_t *color_scale(color_t *dest, color_t *a, COORD_T b);
 color_t *color_add(color_t *dest, color_t *a, color_t *b);
diff --git a/ray.c b/ray.c
index eba29c0..465b154 100644
--- a/ray.c
+++ b/ray.c
@@ -131,11 +131,63 @@ object_t *ray_cast(space_t *s, ray_t *r, COORD_T *dist_ret, bool chk, COORD_T ch
 	return smallest;
 }
 
-static void direct_light(space_t *s, color_t *dest, object_t *o, vector_t *N, vector_t *eye, vector_t *point)
+// Light (l) the object o reflects. Given is the point of intersect, vector to the light l, vector to viewer V, and normal at point N.
+static void reflected_at(object_t *o, color_t *dest, light_t *light, COORD_T dist, vector_t *point, vector_t *l, vector_t *V, vector_t *N) {
+	// Calculate light intensity
+	COORD_T i = light->radiance / ( dist * dist);
+
+	// Calculate Deffuse part
+	color_t tmp;
+	COORD_T cl = vector_dot(l, N) * i;
+	if (cl > 0) {
+		color_scale(&tmp, &light->color, cl * o->m->defuse);
+		color_add(dest, &tmp, dest);
+	}
+
+	// calculate specular part. TODO implement blinn-phong
+	// Calculate R_m
+	vector_t R;
+	vector_scale(&R, N, 2 * vector_dot(l, N));
+	vector_sub(&R, &R, l);
+
+	// Add it to the light
+	cl = vector_dot(&R, V) * i;
+	if (cl > 0) {
+		cl = pow(cl, o->m->shine);
+		color_scale(&tmp, &light->color, cl * o->m->specular);
+		color_add(dest, &tmp, dest);
+	}
+}
+
+// Calculate the contribution of light on o. V is vector to viewer and N is normal at point
+static void contribution_from_pointlight(space_t *s, color_t *dest, object_t *o, light_t *light, vector_t *point, vector_t *V, vector_t *N)
 {
+	vector_t l;
+	
+	// Prepare ray
 	ray_t r;
 	r.start = point;
-	
+
+	// Calculate distance to light
+	vector_sub(&l, &light->point.pos, point);
+	COORD_T d = vector_len(&l);
+
+	// Normalice
+	vector_scale_inv(&l, &l, vector_len(&l));
+
+	// Find obstacles
+	r.direction = &l;
+	object_t *obs = ray_cast(s, &r, NULL, true, d);
+	if (obs) {
+		return;
+	}
+
+	// Calculate the reflected light
+	reflected_at(o, dest, light, d, point, &l, V, N);
+}
+
+static void direct_light(space_t *s, color_t *dest, object_t *o, vector_t *N, vector_t *eye, vector_t *point)
+{
 	// And vector towards viewer
 	vector_t V;
 	vector_sub(&V, eye, point);
@@ -143,47 +195,11 @@ static void direct_light(space_t *s, color_t *dest, object_t *o, vector_t *N, ve
 	// Normalice it
 	vector_scale_inv(&V, &V, vector_len(&V));
 
-	// Cast light rays
+	// Loop lights
 	light_t *light = s->lights;
 	while (light) {
-		vector_t l;
-		
-		// Calculate distance to light
-		vector_sub(&l, &light->pos, point);
-		COORD_T d = vector_len(&l);
-
-		// Normalice
-		vector_scale_inv(&l, &l, vector_len(&l));
-
-		// Find obstacles
-		r.direction = &l;
-		object_t *obs = ray_cast(s, &r, NULL, true, d);
-		if (obs) {
-			light = light->next;
-			continue;
-		}
-		
-		// Calculate Deffuse part
-		color_t tmp;
-		COORD_T cl = vector_dot(&l, N);
-		if (cl > 0) {
-			color_scale(&tmp, &light->defuse, cl * o->m->defuse);
-			color_add(dest, &tmp, dest);
-		}
-
-		// calculate specular part. TODO implement blinn-phong
-		// Calculate R_m
-		vector_t R;
-		vector_scale(&R, N, 2 * vector_dot(&l, N));
-		vector_sub(&R, &R, &l);
-		
-		// Add it to the light
-		cl = 1 * vector_dot(&R, &V);
-		if (cl > 0) {
-			cl = pow(cl, o->m->shine);
-			color_scale(&tmp, &light->specular, cl * o->m->specular);
-			color_add(dest, &tmp, dest);
-		}
+		// Calculate contribution depending on the light type
+		contribution_from_pointlight(s, dest, o, light, point, &V, N);
 
 		light = light->next;
 	}
@@ -278,6 +294,11 @@ int ray_trace_recur(space_t *s, color_t *dest, ray_t *ray, unsigned hop, COORD_T
 	vector_t N;
 	obj_norm_at(o, &N, r.start, ray->direction);
 
+	// Check if emissive
+	if (o->m->emissive > ZERO_APROX) {
+		color_set(&c, o->m->emissive, o->m->emissive, o->m->emissive);
+	}
+
 	// Check if we should calculate light
 	if (o->m->defuse + o->m->specular > ZERO_APROX) {
 		// Add all light hitting o at r.start to c
diff --git a/scene.c b/scene.c
index 730d8c8..6008942 100644
--- a/scene.c
+++ b/scene.c
@@ -90,13 +90,15 @@ object_t *add_object(container_t *cont, unsigned type)
 	return o;
 }
 
-light_t *add_light(container_t *cont)
+light_t *add_light(container_t *cont, unsigned type)
 {
 	light_t *o = container_lig_space(cont);
 	if (!o) {
 		return NULL;
 	}
 
+	o->type = type;
+
 	space_t *s = &cont->space;
 	if (s) {
 		o->next = s->lights;
@@ -112,6 +114,7 @@ light_t *add_light(container_t *cont)
 material_t *add_material(container_t *cont)
 {
 	material_t *m = container_mat_space(cont);
+	memset(m, 0, sizeof(material_t));
 
 	return m;
 }
diff --git a/scene.h b/scene.h
index 08ed9e9..cbaaf3a 100644
--- a/scene.h
+++ b/scene.h
@@ -11,6 +11,9 @@
 #define TYPE_SPHERE 1
 #define TYPE_PLANE 2
 
+#define TYPE_L_POINT 1
+#define TYPE_L_AREA 2
+
 #define CONTAINER_SIZE(objs, mats, ligs) (sizeof(container_t) + objs * sizeof(object_t) + ligs * sizeof(light_t))
 
 typedef struct {
@@ -23,19 +26,13 @@ typedef struct {
 	vector_t norm;
 } plane_t;
 
-typedef struct light_s{
-	vector_t pos;
-	color_t defuse;
-	color_t specular;
-
-	struct light_s *next;
-} light_t;
-
 typedef struct {
 	vector_t color;
 
 	// Light properties
 	COORD_T defuse;
+	// If this object emits light. Only makes sense if combined with a area light.
+	COORD_T emissive; 
 	COORD_T specular;
 	unsigned int shine;
 	
@@ -57,6 +54,23 @@ typedef struct object_s{
 	};
 } object_t;
 
+typedef struct light_s{
+	unsigned type;
+	color_t color;
+
+	COORD_T radiance;
+
+	union {
+		struct {
+			vector_t pos;
+		} point;
+		object_t *area;
+	};
+	struct light_s *next;
+} light_t;
+
+light_t l;
+
 typedef struct {
 	viewpoint_t view;
 	
@@ -102,7 +116,7 @@ container_t *container_init(container_t *c, unsigned objs, unsigned mats, unsign
 space_t *container_prepare_space(container_t *c);
 
 object_t *add_object(container_t *cont, unsigned type);
-light_t *add_light(container_t *cont);
+light_t *add_light(container_t *cont, unsigned type);
 material_t *add_material(container_t *cont);
 
 void obj_norm_at(object_t *o, vector_t *dest, vector_t *point, vector_t *direction);